Generally, the sequence decision of the development and utilization of Chinese mineral resources is based on national and provincial overall plan of the mineral resources. Such plan usually cannot reflect the relative...Generally, the sequence decision of the development and utilization of Chinese mineral resources is based on national and provincial overall plan of the mineral resources. Such plan usually cannot reflect the relative size of the suitability of the development and utilization of mineral resources. To solve the problem, the paper has selected the gift condition, the market condition, the technological condition,socio-economic condition and environmental condition as the starting-points to analyze the influential factors of the priority-sequence of mineral resources' development and utilization. The above 5 conditions are further specified into 9 evaluative indicators to establish an evaluation indicator system. At last,we propose a decision model of the priority sequence based on grey relational analysis method, and figure out the observation objects by the suitability index of development. Finally, the mineral resources of a certain province in China were analyzed as an example. The calculation results indicate that silver(2.0057), coal(1.9955), zinc(1.9442), cement limestone(1.9077), solvent limestone(1.5624) and other minerals in the province are suitable for development and utilization.展开更多
A jack-up platform, with its particular structure, showed obvious dynamic characteristics under complex environmental loads in extreme conditions. In this paper, taking a simplified 3-D finite element dynamic model in...A jack-up platform, with its particular structure, showed obvious dynamic characteristics under complex environmental loads in extreme conditions. In this paper, taking a simplified 3-D finite element dynamic model in extreme storm conditions as research object, a transient dynamic analysis method was proposed, which was under both regular and irregular wave loads. The steps of dynamic analysis under extreme conditions were illustrated with an applied case, and the dynamic amplification factor （DAF） was calculated for each response parameter of base shear, overturning moment and hull sway. Finally, the structural response results of dynamic and static were compared and analyzed. The results indicated that the static strength analysis of the Jack-up Platforms was not enough under the dynamic loads including wave and current, further dynamic response analysis considering both computational efficiency and accuracy was necessary.展开更多
This publication presents an algorithm analyzing dynamic sensitive engineering structures. The measurements data which are analyzed were mostly obtained during test loading of given designs, but some examples are made...This publication presents an algorithm analyzing dynamic sensitive engineering structures. The measurements data which are analyzed were mostly obtained during test loading of given designs, but some examples are made also with simulated data. Data are decomposed in time and frequency domains. Hence, one is able to attain the rate of stress absorption of a given structure, in direct conjunction with the presented algorithm that is based upon the Hilbert transformation. Next, the information in stationary signals that represents a given structure before and after damage, is used to help determine the state of existing objects. Finally, the presented algorithm is capable of an in-depth analysis of new structures and monitoring existing ones, including those which are being exposed to continual use.展开更多
Fracture processes in ship-building structures are in many cases of a 3-D character. A finite element （FE） model of an all fracture mode （AFM） specimen was built for the study of 3-D mixed mode crack fracture beha...Fracture processes in ship-building structures are in many cases of a 3-D character. A finite element （FE） model of an all fracture mode （AFM） specimen was built for the study of 3-D mixed mode crack fracture behavior including modes Ⅰ,Ⅱ, and Ⅲ. The stress intensity factors （SIFs） were calculated by the modified virtual crack closure integral （MVCCI） method, and the crack initiation angle assessment was based on a recently developed 3-D fracture criterion--the Richard criterion. It was shown that the FE model of the AFM-specimen is applicable for investigations under general mixed mode loading conditions, and the computational results of crack initiation angles are in agreement with some available experimental findings. Thus, the applicability of the FE model of the AFM-specimen for mixed mode loading conditions and the validity of the Richard criterion can be demonstrated.展开更多
The governing equations are derived by circumferentially averaging the three-dimensional （3D） Navier-Stokes equations, which are solved using a time marching finite volume approach. Both Euler throughflow model and ...The governing equations are derived by circumferentially averaging the three-dimensional （3D） Navier-Stokes equations, which are solved using a time marching finite volume approach. Both Euler throughflow model and Navier-Stokes （N-S） throughflow model are employed to investigate the performance and flow fields of a highly loaded transonic single-stage fan ATS-2 and a four-stage fan. The results are compared with the experimental and three-dimensional computational results. It shows that the throughflow models can provide reasonable perform- ance characteristics and N-S throughflow model gives better predictions in endwall regions. A throughflow com- putation in which all the non-axisymmetric terms are included has been performed at off-design condition and the radial distributions of the flow field can be well described.展开更多
The structural,electronic properties and formation energies of sulfur and alkaline earth codoped delafossite CuAlO_2 have been investigated using the first-principles density functional theory calculations.Our results...The structural,electronic properties and formation energies of sulfur and alkaline earth codoped delafossite CuAlO_2 have been investigated using the first-principles density functional theory calculations.Our results reveal that the volume of codoping systems increases with the increasing atomic radius of metal atoms.The formation energies under different growth conditions have been calculated,showing that the codoping systems are formed easily under O-rich growth conditions.Electronic band structures and density of states have been obtained.The decreased bandgaps,enhanced covalence and appearance of electron acceptors after codoping are all good for p-type conductivity.展开更多
基金Financial support from the key project of the National Natural Science Foundation of China(No.71273118)is gratefully acknowledged
文摘Generally, the sequence decision of the development and utilization of Chinese mineral resources is based on national and provincial overall plan of the mineral resources. Such plan usually cannot reflect the relative size of the suitability of the development and utilization of mineral resources. To solve the problem, the paper has selected the gift condition, the market condition, the technological condition,socio-economic condition and environmental condition as the starting-points to analyze the influential factors of the priority-sequence of mineral resources' development and utilization. The above 5 conditions are further specified into 9 evaluative indicators to establish an evaluation indicator system. At last,we propose a decision model of the priority sequence based on grey relational analysis method, and figure out the observation objects by the suitability index of development. Finally, the mineral resources of a certain province in China were analyzed as an example. The calculation results indicate that silver(2.0057), coal(1.9955), zinc(1.9442), cement limestone(1.9077), solvent limestone(1.5624) and other minerals in the province are suitable for development and utilization.
基金Supported by the National Natural Science Foundation of China （Grant No.51079034） Fundamental Research Funds for the Central Universities （Grant No. HEUCFRI003）.
文摘A jack-up platform, with its particular structure, showed obvious dynamic characteristics under complex environmental loads in extreme conditions. In this paper, taking a simplified 3-D finite element dynamic model in extreme storm conditions as research object, a transient dynamic analysis method was proposed, which was under both regular and irregular wave loads. The steps of dynamic analysis under extreme conditions were illustrated with an applied case, and the dynamic amplification factor （DAF） was calculated for each response parameter of base shear, overturning moment and hull sway. Finally, the structural response results of dynamic and static were compared and analyzed. The results indicated that the static strength analysis of the Jack-up Platforms was not enough under the dynamic loads including wave and current, further dynamic response analysis considering both computational efficiency and accuracy was necessary.
文摘This publication presents an algorithm analyzing dynamic sensitive engineering structures. The measurements data which are analyzed were mostly obtained during test loading of given designs, but some examples are made also with simulated data. Data are decomposed in time and frequency domains. Hence, one is able to attain the rate of stress absorption of a given structure, in direct conjunction with the presented algorithm that is based upon the Hilbert transformation. Next, the information in stationary signals that represents a given structure before and after damage, is used to help determine the state of existing objects. Finally, the presented algorithm is capable of an in-depth analysis of new structures and monitoring existing ones, including those which are being exposed to continual use.
文摘Fracture processes in ship-building structures are in many cases of a 3-D character. A finite element （FE） model of an all fracture mode （AFM） specimen was built for the study of 3-D mixed mode crack fracture behavior including modes Ⅰ,Ⅱ, and Ⅲ. The stress intensity factors （SIFs） were calculated by the modified virtual crack closure integral （MVCCI） method, and the crack initiation angle assessment was based on a recently developed 3-D fracture criterion--the Richard criterion. It was shown that the FE model of the AFM-specimen is applicable for investigations under general mixed mode loading conditions, and the computational results of crack initiation angles are in agreement with some available experimental findings. Thus, the applicability of the FE model of the AFM-specimen for mixed mode loading conditions and the validity of the Richard criterion can be demonstrated.
基金supported by National Natural Science Foundation of China (50736007, 51006005)
文摘The governing equations are derived by circumferentially averaging the three-dimensional （3D） Navier-Stokes equations, which are solved using a time marching finite volume approach. Both Euler throughflow model and Navier-Stokes （N-S） throughflow model are employed to investigate the performance and flow fields of a highly loaded transonic single-stage fan ATS-2 and a four-stage fan. The results are compared with the experimental and three-dimensional computational results. It shows that the throughflow models can provide reasonable perform- ance characteristics and N-S throughflow model gives better predictions in endwall regions. A throughflow com- putation in which all the non-axisymmetric terms are included has been performed at off-design condition and the radial distributions of the flow field can be well described.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11347199,51402244,and 11547311the Specialized Research Fund for Doctoral Program of Higher Education of China under Grant No.20130184120028+2 种基金the Fundamental Research Fund for the Central UniversitiesChina under Grant Nos.2682014CX084,2682014ZT30,and 2682014ZT31the fund of the State Key Laboratory of Solidification Processing in NWPU under Grant No.SKLSP201511
文摘The structural,electronic properties and formation energies of sulfur and alkaline earth codoped delafossite CuAlO_2 have been investigated using the first-principles density functional theory calculations.Our results reveal that the volume of codoping systems increases with the increasing atomic radius of metal atoms.The formation energies under different growth conditions have been calculated,showing that the codoping systems are formed easily under O-rich growth conditions.Electronic band structures and density of states have been obtained.The decreased bandgaps,enhanced covalence and appearance of electron acceptors after codoping are all good for p-type conductivity.
